Using a Nest thermostat is one of the easiest ways to optimize the day-to-day schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make improvements. But as you can expect, it won’t work properly or at all if you see an error code show up. The exact error code provides useful information about the root of the problem, something a trained technician can use to offer solutions that much sooner.

Listed below are seven of the most likely error codes you may find on your Nest thermostat. We’ll walk you through the basics of each error code along with how you might solve it and the approximate cost to do so. Don’t forget that while the costs will ultimately hinge on the exact Nest model, you can anticipate paying about $75-$200 for repairs. This should also cover travel and labor costs on top of any specific components needed to complete repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and appears when the power is detached from the system. Because this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on the screen until the issue is resolved.

Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection could have appeared further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A knowledgeable technician can check electrical connections and wiring until they locate the source of the problem.

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first complete a factory reset of your thermostat to ensure it’s not just a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin inspecting connectors.

They’ll shut off the power and progressively inspect each wire, ensuring they are fully placed into the connector with the correct amount of bare copper. Once they pinpoint the damaged connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can surface when the weather outside is severely hot. The HVAC system can shut down and stop sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will finally turn off. In the event the breakers are on, you can examine a couple of other places before consulting a professional technician.

Because this error can consume your thermostat’s battery, the first step could be providing enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and deliver power through a USB cable. Assuming it reveals error code 195, you should continue to visually inspect components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to find anything wrong with these components, it’s maybe best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than needed. This may stem from the breaker box, an error from the control board or through a defective connection in the thermostat. Your technician can meticulously examine and test the Nest’s electrical system to determine where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

While this error code isn’t critical, it may still keep you from using the Nest thermostat how you want to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from obtaining adequate power. You can check the Nest’s C connector for the presence of a C wire and adapt the wiring itself if there is. If not, you’ll need a Nest Power Connector.

Due to installation of a Nest Power Connector, you may notice error code E297 show up. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead be required to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.

e104 – Critical

Just like error code e103, e104 is a critical error originating from an overcurrent. If too much power is being delivered inside the Nest’s wiring, it can damage internal components and can even be a fire hazard. If you see this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to turn the power off straightaway. You can then contact a professional technician with the proper experience identifying and solving electrical malfunctions.

e73 – Critical

When your thermostat displays error code e73, it means that the Rc wire is not receiving power.

This could be as easy as the breaker being switched off, but it may also be something with the wiring. After switching off the power to your HVAC system and thermostat, you can visually examine the wires to make sure none of them are loose or damaged. If nothing looks to be out of place, it’s a good idea to speak with a local professional.